Emergence of antibiotic resistance is a major health care concern. Since the discovery of penicillin, at least 17 different classes of antibiotics have been produced. Antibiotic use has become widespread and a cornerstone of medical treatment—being used to treat infections ranging from the seriously life-threatening to the more trivial and frequently non-bacterial illnesses. This constant antibiotic pressure, combined with the ability of bacteria to incorporate DNA from other strains and closely related species, has led to the evolution and acquisition of resistance traits. Multiple-antibiotic-resistant strains are now widespread and bacteria have developed at least one mechanism of resistance (and frequently many more) to every single antibiotic class. For example, Methicillin-resistant Staphylococcus aureus (MRSA) is one of the principal multi-drug resistant bacterial pathogens causing serious community and hospital-acquired infections, such as skin and soft tissue infections, bone, joint and implant infections, ventilator-associated pneumonia, and sepsis. It is estimated that multi-drug resistant Staphylococcus aureus infections leads to 19,000 deaths per year in the United States, with an associated 3-4 billion US dollars in additional annual health care costs. Despite this high mortality rate, there are relatively few new antibacterial agents in the pharmaceutical pipeline. Instead, the majority of antibiotics developed in the last decade are molecules re-engineered from existing antibiotic classes for which underlying resistance mechanisms are already present. Therefore effective new therapeutic options for treatment of infections caused, particularly those caused by multi-drug resistant bacteria are urgently needed.